Stabilized oil-in-water emulsions including agriculturally active ingredients

ABSTRACT

The present invention relates to stable, agricultural oil-in-water emulsion compositions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims the benefit of U.S. Provisional Application61/068,480 filed on Mar. 7, 2008, which is expressly incorporated byreference herein.

FIELD OF THE INVENTION

The present invention relates to stable, agricultural oil-in-wateremulsion compositions.

BACKGROUND AND SUMMARY

Concentrated oil-in water emulsions of liquid active ingredients oractive ingredients dissolved in a solvent are commonly used inagricultural compositions due to certain advantages provided over otherformulation types. Emulsions are water based, contain little or nosolvent, allow mixtures of active ingredients to be combined into asingle formulation and are compatible with a wide range of packagingmaterial. However, there are also several disadvantages of suchagricultural emulsions, namely that they are often complex formulationswhich require high amounts of surface-active agents for stabilization,are generally very viscous, have a tendency for Oswald ripening of theemulsion globules and separate over time. Therefore, improvements insuch emulsion formulations are needed in the agricultural field.

Several oil-in-water emulsion compositions for cosmetics anddermatological applications have been described in U.S. Pat. No.5,658,575; U.S. Pat. No. 5,925,364; U.S. Pat. No. 5,753,241; U.S. Pat.No. 5,925,341; U.S. Pat. No. 6,066,328; U.S. Pat. No. 6,120,778; U.S.Pat. No. 6,126,948; U.S. Pat. No. 6,689,371; U.S. Pat. No. 6,419,946;U.S. Pat. No. 6,541,018; U.S. Pat. No. 6,335,022; U.S. Pat. No.6,274,150; U.S. Pat. No. 6,375,960; U.S. Pat. No. 6,464,990; U.S. Pat.No. 6,413,527; U.S. Pat. Nos. 6,461,625; and 6,902,737; all of which areexpressly incorporated herein by reference. However, although thesetypes of emulsions have found advantageous use in personal careproducts, these types of emulsions have not been used previously withagriculturally active compounds, which are typically present inemulsions at much higher levels than cosmetic active ingredients.

One example of an agricultural oil-in-water emulsion composition that issuitable for agriculturally active ingredients that are liquid orsoluble in suitable solvents at relevant storage temperatures isdisclosed in U.S. patent application Ser. No. 11/495,228, the disclosureof which is expressly incorporated by reference herein.

The present invention is related to agricultural compositions comprisingan oil-in-water emulsion, the oil-in-water emulsion composition havingan oil phase and water phase, the oil-in-water emulsion compositioncomprising an oil adapted to form oily globules having a mean particlediameter of less than 800 nanometers, a monomer being compatible withthe oil phase, an initiator being compatible with the monomer to promotepolymerization, at least one agriculturally active compound, at leastone non-ionic lipophilic surface-active agent, at least one non-ionichydrophilic surface-active agent, at least one ionic surface-activeagent, and water.

DETAILED DESCRIPTION

One embodiment of the present invention is a novel oil-in-water emulsioncomposition having an oil phase and water phase, the oil-in-wateremulsion composition comprising:

an oil adapted to form oily globules having a mean particle diameter ofless than 800 nanometers;

at least one monomer being compatible with the oil phase;

an initiator being compatible with the at least one monomer to promotepolymerization;

at least one agriculturally active compound;

at least one non-ionic lipophilic surface-active agent,

at least one non-ionic hydrophilic surface-active agent;

at least one ionic surface-active agent; and

water.

The oil phase of the oil-in-water emulsion of the present inventionutilizes either an agriculturally active compound which is in the formof an oil, or alternatively, an agriculturally active compound dissolvedor mixed in an oil, to form the oily globules. An oil is by definition,a liquid which is not miscible with water. Any oil which is compatiblewith the agriculturally active compound may be used in the oil-in-wateremulsions of the present invention. The term ‘compatible’ means that theoil will dissolve or mix uniformly with the agriculturally activecompound and allow for the formation of the oily globules of theoil-in-water emulsion of the present invention. Exemplary oils include,but are not limited to short-chain fatty acid triglycerides, siliconeoils, petroleum fractions or hydrocarbons such as heavy aromatic naphthasolvents, light aromatic naphtha solvents, hydrotreated light petroleumdistillates, paraffinic solvents, mineral oil, alkylbenzenes, paraffinicoils, and the like; vegetable oils such as soy oil, rape seed oil,coconut oil, cotton seed oil, palm oil, soybean oil, and the like;alkylated vegetable oils and alkyl esters of fatty acids such asmethyloleate and the like.

An agriculturally active compound is herein defined as any oil solublecompound, hydrophobic compound, or solid compound having a melting pointof below about 95 degrees Celsius or less that shows some pesticidal orbiocidal activity. It is understood to refer to the active compound perse when it is itself an oil or alternatively, the active compounddissolved in an oil of suitable polymeric modifier. Such compounds orpesticides include fungicides, insecticides, nematocides, miticides,termiticides, rodenticides, arthropodicides, herbicides, biocides andthe like. Examples of such agriculturally active ingredients can befound in The Pesticide Manual, 12^(th) Edition. Exemplary pesticideswhich can be utilized in the oil-in-water emulsion of the presentinvention include, but are not limited to, benzofuranyl methylcarbamateinsecticides such as benfuracarb, and carbosulfan; oxime carbamateinsecticides such as aldicarb; fumigant insecticides such aschloropicrin, 1,3-dichloropropene and methyl bromide; juvenile hormonemimics such as fenoxycarb; organophosphate insecticides such asdichlorvos; aliphatic organothiophosphate insecticides such as malathionand terbufos; aliphatic amide organothiophosphate insecticides such asdimethoate; benzotriazine organothiophosphate insecticides such asazinphos-ethyl and azinphos-methyl; pyridine organothiophosphateinsecticides such as chlorpyrifos and chlorpyrifos-methyl; pyrimidineorganothiophosphate insecticides such as diazinon; phenylorganothiophosphate insecticides such as parathion and parathion-methyl;pyrethroid ester insecticides such as bifenthrin, cyfluthrin,beta-cyfluthrin, cyhalothrin, gamma-cyhalothrin, lambda-cyhalothrin,cypermethrin, alpha-cypermethrin, beta-cypermethrin, fenvalerate, andpermethrin; and the like.

Exemplary herbicides which can be used in the oil-in-water emulsion ofthe present invention include, but are not limited to: amide herbicidessuch as dimethenamid and dimethenamid-P; anilide herbicides such aspropanil; chloroacetanilide herbicides such as acetochlor, alachlor,butachlor, metolachlor and S-metolachlor; cyclohexene oxime herbicidessuch as sethoxydim; dinitroaniline herbicides such as benfluralin,ethalfluralin, pendimethalin, and trifluralin; nitrile herbicides suchasbromoxynil octanoate; phenoxyacetic herbicides such as 4-CPA, 2,4-D,3,4-DA, MCPA, and MCPA-thioethyl; phenoxybutyric herbicides such as4-CPB, 2,4-DB, 3,4-DB, and MCPB; phenoxypropionic herbicides such ascloprop, 4-CPP, dichlorprop, dichlorprop-P, 3,4-DP, fenoprop, mecopropand mecoprop-P; aryloxyphenoxypropionic herbicides such as cyhalofop,fluazifop, fluazifop-P, haloxyfop, haloxyfop-R; pyridine herbicides suchas aminopyralid, clopyralid, fluroxypyr, picloram, and triclopyr;triazole herbicides such as carfentrazone ethyl; and the like.

The herbicides can also generally be employed in combination with knownherbicide safeners such as: benoxacor, cloquintocet, cyometrinil,daimuron, dichlormid, dicyclonon, dietholate, fenchlorazole,fenchlorazole-ethyl, fenclorim, flurazole, fluxofenim, furilazole,isoxadifen, isoxadifen-ethyl, mefenpyr, mefenpyr-diethyl, MG191,MON4660, R29148, mephenate, naphthalic anhydride,N-phenylsulfonylbenzoic acid amides and oxabetrinil.

Exemplary fungicides which can be used in the oil-in-water emulsion ofthe present invention include, but are not limited to, difenoconazole,dimethomorph, dinocap, diphenylamine, dodemorph, edifenphos, fenarimol,fenbuconazole, fenpropimorph, myclobutanil, oleic acid (fatty acids),propiconazole, tebuconazole and the like.

It is understood by those skilled in the art that any combination ofagriculturally active compounds may also be used in the oil-in-wateremulsion of the present invention as long as a stable and effectiveemulsion is still obtained.

The amount of agriculturally active ingredient within the oil-in-wateremulsion will vary depending upon the actual active ingredient, theapplication of the agriculturally active ingredient and the appropriateapplication levels which are well known to those skilled in the art.Typically, the total amount of agriculturally active ingredient withinthe oil-in-water emulsion will be from about 1, generally from about 5,preferably from about 10, more preferably from about 15 and mostpreferably from about 20 to about 45, generally to about 40, preferablyto about 35 and most preferably to about 30 weight percent based on thetotal weight of the oil-in-water emulsion.

The synthesized polymer from polymer monomers based on mini-emulsionpolymerization process may be included in the oil phase to retardcrystallization of the agriculturally active ingredient. The synthesizedpolymer permits the use of solid agriculturally active ingredients thathave low solubility in solvent. Examples of such agriculturally activeingredients that may be used in the oil-in-water emulsion composition ofthe present disclosure include Fluroxpyr Meptyl, Chloropyrifos,Chlorpyrifos methyl, Trifluralin, Cyhalofop butyl, Ethalfluralin,Benfluralin, Myclobutanil, Acequinocyl, Alpha-cypermethrin, Amitraz,Bensultap, Beta-cyfluthrin, Beta-cypermethrin, Bifenox, Bifenthrin,Bioresmethrin, Bromoxynil Octanoate, Butralin, Cyflufenamid, Cyfluthrin,Cypermethrin, Diclofop-methyl, Dicofol, Esfenvalerate, Ethalfluralin,Etofenprox, Fenazaquin, Fenoxaprop-P-ethyl, Fenpropathrin, Fenvalerate,Flumiclorac-pentyl, Fluoroglycofen-ethyl, Flurazole, Haloxyfop-etotyl,Indoxacarb, Lambda-cyhalothrin, Metamifop, Methoxychlor, Oxyfluorfen,Pendimethalin, Permethrin, Propaquizafop, Pyributicarb,Quizalofop-P-ethyl, Trifloxystrobin, Bromophos, Fenoxaprop-ethyl,Fluazolate, Nitrofen, and Profluralin.

Suitable monomers for addition to the oil phase have very low watersolubility and good solubility in a mixture of the active ingredient ina molten state with or without additional solvent present. Furthermore,the resulting polymers from monomers based on mini-emulsionpolymerization reaction have very low water solubility and goodsolubility in a mixture of the active ingredient in a molten state withor without additional solvent present. Examples of suitable synthesizedpolymer modifiers may include Polyacrylate, Latex, Polycarbonate,Polyvinyl Acetate homopolymers and copolymers, Polyolefin, Polyurethane,Polyisobutylene, Polybutene, vinyle polymers, Polyester, Polyether,Polyacrylonnitrile, etc.

The initiator may be included in either the oil or aqueous phase of theoil-in-water emulsion to promote polymerization of the monomer whenheated to a specific temperature to active the initiator. A mixture ofdifferent initiators may also be used. Additionally, two different typesof monomer initiators may be used. For example, an oil soluble initiatormay be directly dissolved into the oil phase below the activationtemperature of the initiator while a water soluble initiator may beadded after the emulsion has been created. Examples of suitable monomerinitiators include peroxides and hydroperoxides, azo compounds, redoxinitiators, and certain compounds that from radicals under the influenceof light.

The components of the oil-in-water emulsion are combined using a processdescribed below to produce oily globules having a lamellar liquidcrystal coating. The lamellar liquid crystal coating is an extremelyfine mono- or oligolamellar layer. Oligolamellar layer is understood torefer to a layer comprising from 2 to 5 lipid lamellae. This lamellarliquid crystal coating can be detected by Transmission ElectronicMicroscopy after cryofracture or negative stain, X-Ray diffraction orOptical Microscopy under polarized light. Terms and structure oflamellar crystal liquid phase are well defined in “The Colloidal Domain”second edition, by D. Fennell Evans and H. Wennerstrom, Wiley-VCH(1999), pages 295-296 and 306-307. The oligolamellar layer is comprisedof the non-ionic lipophilic, non-ionic hydrophilic, and ionicsurface-active agents, as stated previously. Preferably, the lipophilicsurface-active agent and the hydrophilic surface-active agent eachcontain at least one optionally saturated and/or branched fattyhydrocarbon chain having more than 12 carbon atoms, preferably from 16to 22 carbon atoms.

Preferably, the lipophilic surface-active agent has an HLB between about2 and about 5. HLB is a standard term known to those skilled in the artand refers to Hydrophilic Lipophilic Balance which identifies theemulsifier's solubility in water or oil.

Lipophilic describes the ability of a material to dissolve in a fat-likesolvent or lipid. The lipophilic surface-active agent is typicallyselected from optionally ethoxylated mono- or polyalkyl ethers or estersof glycerol or polyglycerol, mono- or polyalkyl ethers or esters ofsorbitan (optionally ethoxylated), mono- or polyalkyl ethers or estersof pentaerythritol, mono- or polyalkyl ethers or esters ofpolyoxyethylene, and mono- or polyalkyl ethers or esters of sugars.Examples of lipophilic surface-active agents include, but are notlimited to sucrose distearate, diglyceryl distearate, tetraglyceryltristearate, decaglyceryl decastearate, diglyceryl monostearate,hexaglyceryltristearate, decaglyceryl pentastearate, sorbitanmonostearate, sorbitan tristearate, diethylene glycol monostearate, theester of glycerol and palmitic and stearic acids, polyoxyethylenatedmonostearate 2 EO (containing 2 ethylene oxide units), glyceryl mono-and dibehenate and pentaerythritol tetrastearate.

Hydrophilic describes the affinity of a material to associate withwater. The hydrophilic surface-active agent typically has a HLB of fromabout 8 to about 12 and are typically selected from mono- or polyalkylethers or esters of polyethoxylated sorbitan, mono- or polyalkyl ethersor esters of polyoxyethylene, mono- or polyalkyl ethers or esters ofpolyglycerol, block copolymers of polyoxyethylene with polyoxypropyleneor polyoxybutylene, and mono- or polyalkyl ethers or esters ofoptionally ethoxylated sugars. Examples of hydrophilic surface-activeagents include, but are not limited to polyoxyethylenated sorbitanmonostearate 4 EO, polyoxyethylenated sorbitan tristearate 20 EO,polyoxyethylenated sorbitan tristearate 20 EO, polyoxyethylenatedmonostearate 8 EO, hexaglyceryl monostearate, polyoxyethylenatedmonostearate 10 EO, polyoxyethylenated distearate 12 EO andpolyoxyethylenated methylglucose distearate 20 EO.

In addition to the lipophilic and hydrophilic surface-active agents, anionic surface-active agent also comprises the oligolamellar layer of thelamellar liquid crystal coating.

Ionic surface-active agents which can be used in the oil-in-wateremulsion of the present invention include (a) neutralized anionicsurface-active agents, (b) amphoteric surface-active agents, (c)alkylsulphonic derivatives and (d) cationic surface-active agents.

Neutralized anionic surface-active agents (a) include, but are notlimited to, for example:

-   -   alkali metal salts of dicetyl phosphate and dimyristyl        phosphate, in particular sodium and potassium salts;    -   alkali metal salts of cholesteryl sulphate and cholesteryl        phosphate, especially the sodium salts;    -   lipoamino acids and their salts, such as mono- and disodium        acylglutamates, such as the disodium salt of        N-stearoyl-L-glutamic acid, the sodium salts of phosphatidic        acid;    -   phospholipids; and    -   the mono- and disodium salts of acylglutamic acids, in        particular N-stearoylglutamic acid.

Anionic surface-active agents chosen from alkyl ether citrates andmixtures thereof which can be used in the oil-in-water emulsions of thepresent invention are disclosed in U.S. Pat. No. 6,413,527, which isincorporated herein by reference. Alkyl ether citrates includemonoesters or diesters formed by citric acid and at least oneoxyethylenated fatty alcohol comprising a saturated or unsaturated,linear or branched alkyl chain having from 8 to 22 carbon atoms andcomprising from 3 to 9 oxyethylene groups, and mixtures thereof. Thesecitrates can be chosen, for example from the mono- and diesters ofcitric acid and of ethoxylated lauryl alcohol comprising from 3 to 9oxyethylene groups. The alkyl ether citrates are preferably employed inthe neutralized form at a pH of about 7. Neutralization agents can beingchosen from inorganic bases, such as sodium hydroxide, potassiumhydroxide or ammonia, and organic bases, such as mono-, di- andtriethanolamine, aminomethyl-1,3-propanediol, N-methylglucamine, basicamino acids, such as arginine and lysine and mixtures thereof.

Amphoteric surface-active agents (b) include, but are not limited tophospholipids and especially phosphatidylethanolamine from pure soya.

Alkylsulphonic derivatives (c) include, but are not limited to compoundsof the formula:

in which R represents the radicals C₁₆H₃₃ and C₁₈H₃₇, taken as a mixtureor separately, and M is an alkali metal, preferably sodium.

Cationic surface-active agents (d) include but are not limited tosurface-active agents as disclosed in U.S. Pat. No. 6,464,990, which isincorporated herein by reference. They are typically selected from thegroup of quaternary ammonium salts, fatty amines and salts thereof. Thequaternary ammonium salts include, for example: those which exhibit thefollowing formula:

wherein the R1 to R4 radicals, which can be identical or different,represent a linear or branched aliphatic radical comprising from 1 to 30carbon atoms or an aromatic radical, such as aryl or alkylaryl. Thealiphatic radicals can comprise heteroatoms, such as oxygen, nitrogen,sulfur and halogens. The aliphatic radicals include alkyl, alkoxy,polyoxy(C₂-C₆)alkylene, alkylamido, (C₁₂-C₂₂)alkyl-amido(C₂-C6) alkyl,(C₁₂-C₂₂)alkyl acetate and hydroxyalkyl radicals comprisingapproximately from 1 to 30 carbon atoms; X is an anion selected fromhalides, phosphates, acetates, lactates, (C₂-C₆)alkyl sulfates, andalkyl- or alkylarylsulfonates. Preference is given, as quaternaryammonium salts to tetraalkylammonium chlorides, such asdialkyldimethylammonium and alkyltrimethylammonium chlorides in whichthe alkyl radical comprises approximately from 12 to 22 carbon atoms, inparticularly behenyltrimethyl-ammonium, distearyldimethylammonium,cetyltrimethylammonium and benzyldimethylstearylammonium chlorides, oralternatively, stearamidopropyl-dimethyl(myristyl acetate) ammoniumchloride; imidazolinium quaternary ammonium salts, such as those offormula:

wherein R5 represents an alkenyl or alkyl radical comprising from 8 to30 carbon atoms, for example derived from tallow fatty acids; R6represents a hydrogen atom, an alkyl radical comprising from 1 to 4carbon atoms or an alkenyl or alkyl radical comprising from 8 to 30carbon atoms; R7 represents an alkyl radical comprising from 1 to 4carbon atoms; R8 represents a hydrogen atom or an alkyl radicalcomprising from 1 to 4 carbon atoms; and X is an anion selected from thegroup of the halides, phosphates, acetates, lactates, alkyl sulfates, oralkyl, and alkylarylsulfonates. R5 and R6 preferably denote a mixture ofalkenyl or alkyl radicals comprising from 12 to 21 carbon atoms, forexample derived from tallow fatty acids, R7 preferably denotes a methylradical and R8 preferably denotes hydrogen. Quaternary diammonium saltsare also contemplated, such as propanetallowdiammonium dichloride.

Fatty amines include, but are not limited to those of formula:R9(CONH)_(n)(CH₂)_(m)N(R11)R10wherein R9 is an optionally saturated and/or branched hydrocarbon chain,having between 8 and 30 carbon atoms, preferably between 10 and 24carbon atoms; R10 and R11 are selected from H and an optionallysaturated and/or branched hydrocarbon chain, having between 1 and 10carbon atoms; preferably between 1 and 4 carbon atoms;

-   m is an integer between 1 and 10 and is preferably between 1 and 5;    and n is either 0 or 1.

Examples of fatty amines include, but are not limited to, stearylamine,aminoethyl-ethanolamide stearate, diethylenetriamine stearate,palmitamidopropyldimethyl-amine, palmitamidopropyldiethylamine,palmitamidoethyldiethylamine, palmitamidoethyldimethylamine.Commercially available fatty amines include, but are not limited to,Incromine™ BB from Croda, Amidoamine™ MSP from Nikkol, and Lexamine™series from Inolex, the Acetamine series from Kao Corp; Berol 380, 390,453 and 455, and Ethomeen™ series from Akzo Nobel, and Marlazin™ L10,OL2, OL20, T15/2, T50 from Condea Chemie.

As described above, the surface-active agents form the lamellar liquidcrystal coating of the oily globules suspended within the aqueous phaseof the oil-in-water emulsion of the present invention. The amount of thethree surface-active agents utilized in the oil-in-water emulsion of thepresent invention is typically from about 20, preferably from about 35to about 65, preferably to about 55 weight percent of non-ioniclipophilic surface-active agent, from about 15, preferably from about 25to about 50, preferably to about 40 weight percent of non-ionichydrophilic surface-active agent and from about 5, preferably from about10 to about 45, preferably to about 35 weight percent of ionicsurface-active agent; based on the total combined weight of surfaceactive agents. The coating of the oily globules comprises a total amountof hydrophilic surface-active agent, lipophilic surface-active agent andionic surface-active agent to be between about 2 and about 20 percent byweight, based on the total weight of the oil-in-water emulsion.Preferably the total amount is from about 2.5, more preferably fromabout 3 to 10, more preferably to about 6 weight percent, based on thetotal weight of the oil-in-water emulsion.

The ratio of the total weight of the surface-active compounds to thetotal weight of oil is typically from 1:2.5 to 1:25.

The amount of the monomer in the oil-in-water emulsion of the presentdisclosure is typically from about 0.2, preferably from about 2 to about40, more preferably from 5% to about 20 weight percent based on thetotal weight of the oil-in-water emulsion. The amount of initiator inthe oil-in-water emulsion is typically from about 0.01 to about 1 weightpercent based on the total weight of the oil-in-water emulsion.

The aqueous phase is typically water, for example, deionized water. Theaqueous phase may also contain other additives such as compounds thatlower the freezing point, for example alcohols, e.g. isopropyl alcoholand propylene glycol; pH buffering agents, for example alkali phosphatessuch as sodium phosphate monobasic monohydrate, sodium phosphatedibasic; biocides, for example Proxel GXL; and antifoams, for exampleoctamethylcyclotetrasiloxane (Antifoam A from Dow Corning). Otheradditives and/or adjuvants can also be present in the aqueous phase aslong as the stability of the oil-in-water emulsion is still maintained.Other additives also include water-soluble agriculturally activecompounds.

The oil phase or the coated oily globules are from 5, preferably from 8and more preferably from 10 to 50 percent, preferably to 45 and mostpreferably to 40 weight percent, based on the total weight of theoil-in-water emulsion composition. The oil/water ratio is typically lessthan or equal to 1.

Other additives and/or adjuvants can also be present within theoil-in-water emulsion of the present invention, as long as the stabilityand activity of the oil-in-water emulsion is still obtained. Theoil-in-water emulsions of the present invention may additionally containadjuvant surface-active agents to enhance deposition, wetting andpenetration of the agriculturally active ingredient onto the targetsite, e.g. crop, weed or organism. These adjuvant surface-active agentsmay optionally be employed as a component of the emulsion in either theoil or water phase, or as a tank mix component; the use of and amountdesired being well known by those skilled in the art. Suitable adjuvantsurface-active agents include, but are not limited to ethoxylated nonylphenols, ethoxylated synthetic or natural alcohols, salts of the estersor sulphosuccinic acids, ethoxylated organosilicones, ethoxylated fattyamines and blends of surface-active agents with mineral or vegetableoils.

The oil-in-water emulsion of the present invention can be preparedaccording to the process described in U.S. Pat. No. 5,925,364, theteachings of which are incorporated herein by reference. Theagriculturally active ingredient or a combination of agriculturallyactive ingredients is first melted or dissolved into the polymericmonomers, adding solvent if desired, after which the nonionicsurface-active agent(s) is dissolved into the mixture. Then the mixtureis homogenized by cavitation using a high pressure homogenizer, toprovide the small particle sized oily globules. The mean size of thecoated oily globules is typically less than 800 nanometers, preferablyless than 500 nanometers and most preferably about 200 nanometers, asdetermined using laser diffraction particle size analysis and scanningelectron microscopy. Once the desirable particle size is reached, theemulsion is heated up to the desired monomer activation temperature toinitialize polymerization reaction within oil droplets. The temperatureis then kept at constant for a certain time to finish the polymerizationreaction.

In one embodiment, the oil-in-water emulsion is prepared by:

-   -   1) melting or dissolving an agriculturally active ingredient(s)        into a monomer or monomer mixture and optionally a suitable        solvent or monomer initiator;    -   2) mixing an oil phase (A), comprising the lipophilic        surfactant, the monomer containing the dissolved agriculturally        active ingredient(s), the hydrophilic surfactant, the ionic        surfactant, an agriculturally active compound and optionally a        suitable solvent and (B) an aqueous phase optionally including a        monomer initiator (or the water soluble initiator could be added        after homogenization process) to obtain a mixture; and    -   3) homogenizing the mixture by subjecting the mixture to        cavitation.    -   4) Heating the emulsion up to the desired monomer activation        temperature to initialize polymerization reaction within oil        droplets. The temperature is then kept at constant for a certain        time to finish the polymerization reaction.

In the first step, the mixture can be formed by conventional stirring,for example, using a high shear homogenizer rotating at a rate ofapproximately between 2000 and 7000 rpm for a time approximately between5 and 60 minutes and at a temperature at least 5 to 10° C. belowinitiator activation temperature. The temperature of the emulsion duringthe homogenization should be also controlled to be at least 5 to 10° C.below the monomer initiator activation temperature to prevent thepolymerization reaction from occurring within the homogenizer.

The homogenization can be performed by using a high pressure homogenizeroperating at pressures between approximately 200 and 1000 bar as is wellknown to those skilled in the art. The process is performed bysuccessive passages, generally from 1 to 12 passages, at a selectedpressure; the mixture being returned to normal pressure between eachpassage. The homogenization of the second step may also be carried outunder the action of ultrasound or alternatively by the use of ahomogenizer equipped with a rotor-stator type head.

Another embodiment of the present invention is the use of theoil-in-water emulsion in agricultural applications to control, preventor eliminate unwanted living organisms, e.g. fungi, weeds, insects,bacteria or other microorganisms and other pests. This would includeits' use for protection of a plant against attack by a phytopathogenicorganism or the treatment of a plant already infested by aphytopathogenic organism, comprising applying the oil-in-water emulsioncomposition, to soil, a plant, a part of a plant, foliage, flowers,fruit, and/or seeds in a disease inhibiting and phytologicallyacceptable amount. The term “disease inhibiting and phytologicallyacceptable amount” refers to an amount of a compound that kills orinhibits the plant disease for which control is desired, but is notsignificantly toxic to the plant. The exact concentration of activecompound required varies with the fungal disease to be controlled, thetype of formulations employed, the method of application, the particularplant species, climate conditions, and the like, as is well known in theart.

Additionally, the oil-in-water emulsions of the present invention areuseful for the control of insects or other pests, e.g. rodents.Therefore, the present invention also is directed to a method forinhibiting an insect or pest which comprises applying to a locus of theinsect or pest an oil-in-water emulsion comprising an insect-inhibitingamount of an agriculturally active compound for such use. The “locus” ofinsects or pests is a term used herein to refer to the environment inwhich the insects or pests live or where their eggs are present,including the air surrounding them, the food they eat, or objects whichthey contact. For example, insects which eat or contact edible orornamental plants can be controlled by applying the active compound toplant parts such as the seed, seedling, or cutting which is planted, theleaves, stems, fruits, grain, or roots, or to the soil in which theroots are growing. It is contemplated that the agriculturally activecompounds and oil-in-water emulsions containing such, might also beuseful to protect textiles, paper, stored grain, seeds, domesticatedanimals, buildings or human beings by applying an active compound to ornear such objects. The term “inhibiting an insect or pest” refers to adecrease in the numbers of living insects or pests, or a decrease in thenumber of viable insect eggs. The extent of reduction accomplished by acompound depends, of course, upon the application rate of the compound,the particular compound used, and the target insect or pest species. Atleast an inactivating amount should be used. The terms “insect orpest-inactivating amount” are used to describe the amount, which issufficient to cause a measurable reduction in the treated insect or pestpopulation, as is well known in the art.

The locus to which a compound or composition is applied can be any locusinhabited by an insect, mite or pest, for example, vegetable crops,fruit and nut trees, grape vines, ornamental plants, domesticatedanimals, the interior or exterior surfaces of buildings, and the soilaround buildings.

Because of the unique ability of insect eggs to resist toxicant action,repeated applications may be desirable to control newly emerged larvae,as is true of other known insecticides and acaricides.

Additionally, the present invention relates to the use of oil-in-wateremulsions comprising agriculturally active compounds which areherbicides. The term herbicide is used herein to mean an activeingredient that kills, controls or otherwise adversely modifies thegrowth of plants. An herbicidally effective or vegetation controllingamount is an amount of active ingredient which causes an adverselymodifying effect and includes deviations from natural development,killing, regulation, desiccation, retardation, and the like. The termsplants and vegetation include emerging seedlings and establishedvegetation.

Herbicidal activity is exhibited when they are applied directly to thelocus of the undesirable plant thereof at any stage of growth or beforeemergence of the weeds. The effect observed depends upon the plantspecies to be controlled, the stage of growth of the plant, the particlesize of solid components, the environmental conditions at the time ofuse, the specific adjuvants and carriers employed, the soil type, andthe like, as well as the amount of chemical applied. These and otherfactors can be adjusted as is known in the art to promote selectiveherbicidal action. Generally, it is preferred to apply such herbicidespost emergence to relatively immature undesirable vegetation to achievethe maximum control of weeds.

Another specific aspect of the present invention is a method ofpreventing or controlling pests such as nematodes, mites, arthropods,rodents, termites, bacteria or other microorganisms, comprising applyingto a locus where control or prevention is desired a composition of thepresent invention which comprises the appropriate active compound suchas a nematocide, miticide, arthropodicide, rodenticide, termiticide orbiocide.

The actual amount of agriculturally active compound to be applied toloci of disease, insects and mites, weeds or other pests is well knownin the art and can readily be determined by those skilled in the art inview of the teachings above.

The following examples are provided to illustrate the present invention.The examples are not intended to limit the scope of the presentinvention and they should not be so interpreted. Amounts are in weightparts or weight percentages unless otherwise indicated.

EXAMPLES

These examples are provided to further illustrate the invention and arenot meant to be construed as limiting.

As disclosed herein, all temperatures are given in degrees Celsius andall percentages are weight percentages unless otherwise stated.

In these examples, the process is performed using the followingprocedure:

The agriculturally active ingredient is melted or dissolved into themonomer and optional a solvent. The monomer mixture optionally includingan initiator is then mixed into the oil phase A. The oil phase A and theaqueous phase B are heated separately to the desired temperature. PhaseA is poured into Phase B, with stirring of 4000-8000 rpm provided by aSilverson L4RT high shear homogenizer fitted with a square hole highshear screen. Stirring and temperature conditions are maintained for 10minutes.

The mixture is then introduced into a Niro Soavi high pressure 2-stagehomogenizer of type Panda 2K, which is adjusted to a pressure of500-1000 bar for 1 to 12 successive passages.

Once the desirable particle size is reached, the emulsion is heated upto the desired monomer activation temperature to initializepolymerization reaction within oil droplets. The temperature is thenkept at constant for a certain time to finish the polymerizationreaction.

A stabilized oil-in-water emulsion is thus obtained, the oily globulesof which have a mean diameter of typically around 200-400 nm.

Example 1 Trifluralin Oil-in-Water Emulsion

wt % Oil Phase A Trifluralin 30.00 Methyl Acrylate 5.00 Diglycerolmonostearate (Nikkol DGMS by Nikko 2.57 Chemical Co.) Sorbitan (40EO)stearate (Tween 61 by Uniqema) 1.93 N,N-Dimethyl Fatty Acid Amide 12.002,2′-azobis(2,4-dimethylpentanenitrile) 0.15 Aqueous Phase B Deionizedwater 37.55 Cedepal 0.50 Proxel GXL Biocide 0.30 Propylene Glycol 10.00

The sample showed no crystal formation after two month storage at 5° C.A conventional Trifluralin oil-in-water emulsion made without themonomer (Methyl Acrylate) or initiator(2,2′-azobis(2,4-dimethylpentanenitrile)) was also made for comparison.This sample had very similar initial mean particle size anddistribution. The sample destabilized after the sample was stored at 5°C. for two months due to crystallization of the Trifluralin.

Example 2 Myclobutanil Oil-in-Water Emulsion

wt % Oil Phase A Myclobutanil 4.50 Methyl Acrylate 10.00 Brij 72 2.65Sorbitan (40EO) stearate (Tween 61 by Uniqema) 1.85 A150 ND 10.002,2′-azobis(2,4-dimethylpentanenitrile) 0.09 Aqueous Phase B Deionizedwater 60.11 Cedepal 0.50 Proxel GXL Biocide 0.30 Propylene Glycol 10.00

The samples showed no sign of crystal formation, after two monthsstorage at 0° C. A conventional Myclobutanil oil-in-water emulsionwithout the monomer (Methyl Acrylate) or initiator(2,2′-azobis(2,4-dimethylpentanenitrile)) was also made for comparison.This sample included 20% A150ND solvent (compared to 10% in theexample), and had very similar initial mean particle size anddistribution. The sample destabilized after two months storage at 0° C.due to crystallization of the Myclobutanil.

Example 3 Myclobutanil Oil-in-Water Emulsion

wt % Oil Phase A Myclobutanil 4.50 Methyl Acrylate 20.00 Brij 72 2.65Sorbitan (40EO) stearate (Tween 61 by Uniqema) 1.85 A150 ND 10.002,2′-azobis(2,4-dimethylpentanenitrile) 0.12 Aqueous Phase B Deionizedwater 50.08 Cedepal 0.50 Proxel GXL Biocide 0.30 Propylene Glycol 10.00

The samples showed no crystal formation after two months storage at 0°C. A conventional Myclobutanil oil-in-water emulsion without the monomer(Methyl Acrylate) or initiator (2,2′-azobis(2,4-dimethylpentanenitrile))was also made for comparison. This sample included 20% A150ND solvent,and had very similar initial mean particle size and distribution. Thesample destabilized after two months storage at 0° C. due tocrystallization of the Myclobutanil.

What is claimed is:
 1. An oil-in-water emulsion composition having anoil phase and water phase, the oil phase comprising: at least onemonomer being compatible with the oil phase and insoluble in water; aninitiator being compatible with at least one monomer to promotepolymerization; at least one agriculturally active compound; at leastone non-ionic lipophilic surface-active agent; at least one non-ionichydrophilic surface-active agent; and at least one ionic surface-activeagent.
 2. The composition of claim 1 wherein the non-ionic lipophilicsurface-active agent has an Hydrophilic Lipophilic Balance of between 2and
 5. 3. The composition of claim 2, wherein the non-ionic lipophilicsurface-active agent is selected from the group consisting of: sucrosedistearate, diglyceryl distearate, tetraglyceryl tristearate,decaglyceryl decastearate, diglyceryl monostearate,hexaglyceryltristearate, decaglyceryl pentastearate, sorbitanmonostearate, sorbitan tristearate, diethylene glycol monostearate,polyoxyethylenated monostearate 2 EO, and pentaerythritol tetrastearate.4. The composition of claim 1, wherein the non-ionic hydrophilicsurface-active agent has an Hydrophilic Lipophilic Balance between 8 and12.
 5. The composition of claim 4, wherein the non-ionic hydrophilicsurface-active agent is selected from the group consisting of monoalkylethers of polyethoxylated sorbitan, monoalkyl esters of polyethoxylatedsorbitan, polyalkyl ethers of polyethoxylated sorbitan, polyalkyl estersof polyethoxylated sorbitan, monoalkyl ethers of polyoxyethylene,monoalkyl esters of polyoxyethylene, polyalkyl ethers ofpolyoxyethylene, polyalkyl esters of polyoxyethylene, monoalkyl ethersof polyglycerol, monoalkyl esters of polyglycerol, polyalkyl ethers ofpolyglycerol, polyalkyl esters of polyglycerol, block copolymers ofpolyoxyethylene with polyoxypropylene, block copolymers ofpolyoxyethylene with polyoxybutylene, monoalkyl ethers of optionallyethoxylated sugars, monoalkyl esters of optionally ethoxylated sugars,polyalkyl ethers of optionally ethoxylated sugars, and polyalkyl estersof optionally ethoxylated sugars.
 6. The composition of claim 5, whereinthe non-ionic hydrophilic surface-active agent is selected from thegroup consisting of polyoxyethylenated sorbitan monostearate 4 EO,polyoxyethylenated sorbitan tristearate 20 EO, polyoxyethylenatedsorbitan tristearate 20 EO, polyoxyethylenated monostearate 8 EO,hexaglyceryl monostearate, polyoxyethylenated monostearate 10 EO,polyoxyethylenated distearate 12 EO and polyoxyethylenated methylglucosedistearate 20 EO.
 7. The composition of claim 1, wherein the ionicsurface-active agent is selected from the group consisting of (a)neutralized anionic surface-active agents, (b) amphoteric surface-activeagents, (c) alkylsulphonic derivatives and (d) cationic surface-activeagents.
 8. The composition of claim 7, wherein the ionic surface-activeagent is selected from the group consisting of: alkali metal salts ofdicetyl phosphate; alkali metal salts of dimyristyl phosphate; alkalimetal salts of cholesteryl sulphate; alkali metal salts of cholesterylphosphate; lipoamino acids; salts of lipoamino acids; the sodium saltsof phosphatidic acid; phospholipids; monosodium salts of acylglutamicacids; disodium salts of acylglutamic acids; and alkyl ether citrates.9. The composition of claim 7, wherein the ionic surface-active agent isa phospholipid.
 10. The composition of claim 7, wherein the ionicsurface-active agent is an alkylsulphonic derivative.
 11. Thecomposition of claim 7, wherein the ionic surface-active agent isselected from the group consisting of quaternary ammonium salts, fattyamines and salts thereof.
 12. The composition of claim 1, wherein theagriculturally active compound is selected from a group consisting offungicides, insecticides, nematocides, miticides, biocides,termiticides, rodenticides, arthropodicides, and herbicides.
 13. Thecomposition of claim 1, wherein the monomer is selected in such way thatthe synthesized polymer is compatible with the oil phase, and insolublein water.
 14. The composition of claim 1, further comprising a secondmonomer.
 15. The composition of claim 1, wherein the initiator is eitheroil soluble or water soluble.
 16. The composition of claim 1, whereinthe oil-in-water emulsion composition is from about 1 to about 60 weightpercent total oil phase, from about 0.2 to about 40 weight percentmonomer, from about 0.01 to about 1.0 weight percent initiator, fromabout 1 to about 45 weight percent agriculturally active compound, fromabout 0.4 to about 13 weight percent non-ionic lipophilic surface-activeagent, from about 0.3 to about 10 weight percent non-ionic hydrophilicsurface-active agent, from about 0.1 to about 9 weight percent ionicsurface-active agent, based on a total weight of the oil-in-wateremulsion composition.